ATLANTA — When Zell Miller wanted a lottery in 1992, the then-Democratic governor traveled across Georgia to rally voter support.

Republican Gov. Sonny Perdue campaigned for a constitutional ban on same-sex marriage 12 years later, and Republican Gov. Nathan Deal and Atlanta Mayor Kasim Reed, a Democrat, urged Georgians this year to approve a tax hike to raise billions of dollars for transportation projects.

Miller and Perdue were victorious. The transportation tax got hammered in metro Atlanta and across much of the rest of Georgia. The common thread was the high-profile electioneering by leading elected officials.

It’s happening again this year amid a fierce battle over a constitutional amendment that would affirm the state’s authority to approve independent charter schools. But this time, lawsuits are involved.

Deal is among the amendment backers who argue it’s a matter of offering more educational options. State Schools Superintendent John Barge, along with many local superintendents and school board members, lead the opposition. They say the amendment would strip power from local school boards that now can approve or reject applications for charters and could siphon money from existing schools.

Separate groups of citizens who back the amendment have sued in Fulton and Gwinnett counties, asking courts to block local school systems from any activity opposing the amendment. Georgia law generally restricts public officials and employees from using taxpayer money for blatant campaign activities, including on ballot measures. A 1981 Georgia Supreme Court ruling says spending “public money to influence the citizens and voters ... contains within it the possibility of the corrupt use of influence to perpetuate a local administration’s power.”

The question is how far that restriction extends: Do spending money on travel and spending time arguing a position amount to a de facto public expense? Must elected officials accept a muzzle when they take their oath of office?

Although they are on opposite sides, Barge and Deal stand beside their actions.

“When issues of public education arise, I believe it’s an expectation of those people who supported me (in the 2010 election) to keep them informed,” Barge said. “I felt it was important for the people who put their confidence in me to know how I feel.”

Deal spokesman Brian Robinson said, “The governor hasn’t and won’t use official resources to ‘campaign’ on behalf of an issue or candidate on the ballot. But the governor is duty bound to tell Georgians where he stands on the most important issues facing the state.”

Glenn Delk, an attorney who represents the citizens group suing the Fulton County school system, said the law clearly intends to place a strict ban on electioneering of any kind. That, he said, includes anything from expressing an opinion in an official capacity to passing a resolution as a full board or allowing opposition to be discussed at an after-school faculty meeting on a campus.

Delk hasn’t gotten very far in court.

A Fulton County judge denied a request to order the Fulton schools to remove information about the amendment from the system’s website. Judge Wendy Shoob told Delk she interpreted the law as forbidding the use of taxpayer money on clear campaign expenses: advertising, consulting, voter turnout efforts. She expressed skepticism about Delk’s view on elected officials’ public statements.

“So they can’t speak if they have a title?” she asked.

Both the Fulton and Gwinnett cases are still pending. Separately, Delk pressured Barge into declaring the Department of Education’s neutrality, removing documents about the amendment from the agency’s official website and soliciting from Attorney General Sam Olens an opinion about local school boards’ activities.

Authorities still have “their First Amendment right to express their personal opinions so long as they do not use public resources to do so,” Olens wrote.

Barge told local officials he would take no action against them. But Emmet Bondurant, an attorney who is advising the opposition groups, said Delk’s threats and Olens’ letter have had a chilling effect, making public officials reticent to do what Bondurant says the law clearly allows. He said there is no practical distinction between an elected official’s public role and their status as an individual.

“There is absolutely no prohibition against public officials speaking out on various issues that may come before the electorate,” he said.

Bondurant, who has represented clients in cases involving the same issues, went a step further. He noted that local school boards have a constitutional mandate to act in support of education. A broad application of that provision, he said, would allow the activities that Delk says are illegal.

Bert Brantley, a consultant for the charter amendment’s proponents, said the debate should be about the merits of the policy proposal, adding that he has no problem with Barge expressing his opposition. “I don’t think we should, at all, have elected officials who are elected in the political process then not be able to participate in the political process,” Brantley said.

Brantley also advised the campaign in favor of the transportation tax and, before that, worked as Perdue’s spokesman. Brantley noted that Perdue would not raise money for his campaign from the governor’s office, instead going to the Governor’s Mansion to make phone calls. But the mansion, he noted, is publicly supported. And the governor is always accompanied by his state-paid security, whether he’s at an official function or a campaign event.

“This is a constant tension when you have these issues on the ballot,” Brantley said. “I think it’s just a matter of practicality.”